A father of three girls has launched a petition to stop schools from dismissing period pain as an “authorised” reason for missing lessons.
Marcus Alleyne, 37, of St Austell in Cornwall, said the matter came to a head last week when his eldest daughter, 13-year-old Izzy, felt ill.
When he contacted her secondary school to alert them that she would be off ill that day, he was asked what was wrong with her, PlymouthLive reports.
After explaining she was feeling "really rotten" and was suffering "serious period pains”, he was told this was not a legitimate reason and she would be marked as an "unauthorised absence”.
Marcus, who is a former Royal Navy medic and vice-chair of Black Voices Cornwall, as well as being an award-winning musician, classically-trained choral and orchestral conductor and music director, said he was appalled at the response.

He said: “If I had said she was suffering a migraine then wouldn't be having this conversation.
"It got me thinking about what we could do. I contacted the school to schedule a meeting with the student welfare officer, but I haven't heard anything yet.”
After speaking with his wife Jo and Izzy, he launched a petition with the challenge "Period Pains (dysmenorrhea) need to be a legitimate reason for absence in schools”.
Describing himself as a "proud father of incredibly courageous, fierce and strong girls”, he went on to write: “I'm sure many women would agree, that at some stage, they have suffered significantly from Dysmenorrhoea [the term used to describe painful periods], yes there is actually a medical term for ‘period pains’.
"The reason for this terminology is due to its being a globally recognised medical condition, with a variety of treatment approaches, from over the counter pain relief and a hot water bottle to surgical interventions.
"By not allowing absences due to Dysmenorrhoea, which you are doing by considering them unauthorised, shows very clear disparities, and registering absences as unauthorised due to a medical condition only affecting women is a clear demonstration.”

He went on to question how many young women were being dismissed within the education setting "as a result of diminishing their experiences, and unilaterally deciding that their discomfort does not matter".
Significant changes need to be made not only in schools but also in wider policy, he urged, in order to “educate prehistoric mindsets”.
He said he has been overwhelmed by the positive response to his petition, with many other parents - especially mothers - supporting his rousing words and highlighting that they were particularly pleased to see a man taking this supportive stance of his daughters.
One wrote: "I wish I could sign this petition a million times!!! Not only are all the points valid and important, but I’m am so, so proud that this has been brought to the table for addressing by a man!
“Showing other men that they can make a difference to the world if they too stand up against inequality and sexism.
“It’s not just a women’s issue it’s a human rights issue, don’t leave us to fight the discrimination alone.
“Well done to this father, standing up for your girls and all girls and menstruating people. Amazing."